Gear-cutting machine.



l. A. SVENSSON.

GEAR CUTING MACHINE.

APFucATioNflLfo SEPT. s, |909.

Patente June 15, 1915.

12 SHEETS-SHEET 1.

@Wi/kwam@ J. A. SVENSSON.

GEAR CUTTING MACHINE.

APPLICATION man sEPT.a. 1909.

1,143,602. Patented June 15, 1915.

12 SHEETS-SHEET 2.

J. SVENSSON.

GEAR CUTTING MACHINE.

MPucATmN msn sans, 1909.

Patented June 15, 1915.

l2 SHEETS-SHEET 3.

L'A. SVENSSON.

GEAR CUTTING MACHINE.

APPLICATION FILED SEPT. 8. 1909.

Patented June 15, 1915.

l2 SHETS-SHEET 4.

lllx Il l?! l. A. SVENSSON.

GEAR CUTTAING MACHINE. APPLICATION man SEPT. a. 1909.

Patented June 15, 1915.

12 SHEETS-SHEET 5.

l J. A. SV EjjNSSoN.

' GEAR CUTUNG MACHINE.

APPLiCATlON FILED SEPT.8, 1909.

1,143,502. n Patented June 15, 1915.

12 SHEETS-SHEET 6.

l. A. SVENSSON- Y 'Patelltd 311116 15, 1915.

12 SHEETS-SHEET 1.

'GEAR CUTTING MACHINE. APPLICATION FILED SEPT'. 8. 1909.

J. A. SVENSSON.

GEAR CUTTING MACHINE.

APPLICATION mep sin. s, 1909.

12 SHEETS-SHEET 9* www NQ 3. A. SVENSSGN.

GEAR CUTTNG MACHINE.

APPLICATION man SEPT. a, 19.39.

` atente June l5, 1915.

12 SHEETS-SHEET X0.

l.. .m w Sm I@ JWN M .A1

mw N

J. A. SVENSSGI'l GEAR CUTTING MACHINE. APPLlcATloM FILED SEPT. 8. 1909.

Patented Jung 15, 1915.

12 SHEETS-SHEET ll.

. '1.A.svENssoN.Y

i amcumus mums.

Patenhd June 1 5, y1915.

-l: interianzu 12.

APPLICATIPI FILED SEPT, 8. i909.

.roe' and State of la MCE .Tonen ALFRED svnNssoN, or noonns'rnn, NEWvonk..`

enen-CUTTING MAINE.

mienne.

Specieation of Letters Patent.

Application filed September 8, 1909. Serial No. 516,708.

To all 'whom t may concern:

Be it known that JOHAN ALFRED Svensson', a citizen of the United States,and a resident of Rochester, in the county of Mon- Yew York, haveinvented certain new and useful Improvements in Gear-Cutting Machines,of Which the following is a specification.

This invention relates to improvements in gear cutting machinesapplicable for cutting spur, spiral and bevel gears. Y

The invention comprises mechanism .by which the cutting tools,preferably a pair of them, are caused to assume consecutive operativepositions, and While the gear blank is traveling in the same directionwith the cutting tools. When cutting spur and spiral gears theconsecutive positions constitute an imaginary rack, and for bevel gearsthe consecutive positions of the cutting tools are the path of the teethof an imaginary crown gear meshing with the bevel gear blank.`

The invention also .contains means to automatically index the gearbla-nkv operated upon for every cutting stroke of the tools, to produceabout the same degree of completion on all the teeth during the cuttingoperation.

In the accompanying drawings which hereby are made a part of thisspeciiication Figure l is afront elevation of the invention, partsthereof being shown in section, adapted to out spur gears. Fig. 2 is apartial front view of the gear blank carrying device shown in Fig. l,tilted in position for a bevel gear blank, contiguous parts being shownin section. Fig. 3 is a top plan view of Fig. l. Fig. 4 is an enlargedright hand side elevation of Fig. l with some of the elements in achanged position. Fig. 5 is an enlarged lett hand side elevation of Fig.l. Fig. 6 is an enlarged partial right hand side elevation of Fig. l.Fig. 7 is a section on the line 7-7 of Fig. 8. Fig. 8 is an enlargedpartial sectional elevation of Fig. 3 on the line Ef-8, showingparticularly the driving and indexing mechanism. Fig. 9 is an enlarged.

partial top plan view of Fig. l, showing particularly the feedtransmitting gearing. Fig. 1G is a partial section on the line l0-10 olFig. 1l. Fig. 11 is an enlarged portion of Fig. 6. Fig. l2 is a partialsection on the line 12--12 of Fig. ll. Fig. 13 is a partial section onthe line 13--13 of Fig. 5. Fig. 14 isa partial sectional front elevationof Fig. l5 on the line lli-14. lFig. 15 is a partial enlavrged section.on the line 15 l5 of Fig. l. Fig. 16 is an isometrical elevation of theraten-tea June i5, 1era.

driving and feed shafts With their respective gears,'the contiguousparts of the machine being omitted. Fig. l? is a dia-grammatical bottomplan view of the cutting tools in .their initial positions for a spurgear blank. Fig. 18 is a view similar to that shown on Fig. 17 'with thecutting tools advanced to their central positions. Fig. i9 is adiagrammatical rear elevation of Fig. 18. Fig. 20 is a vieu similar toFig. l? with the cutting tools at the opposite end of their travels.TFig. 2l is' a dlagrammatical rear elevation showing the 'centralposition of the cutting tools adapted to operate on the spiral gear.

Fig. 22 is a diagrammatical bottom plan view of Fig. 2l. Fig. 23 isadiagrammatical bottom plan view of theposition'of the cutting tools whenboth of saidtools are cutting on a'single tooth of a bevel gear. Fig. 24is a diagrammatical rear elevation of Fig. 23. Fig. 25 is adiagrammatical bottom plan view of the ,cutting tools arranged for simultaneously cutting two teeth of a bevel gear.

Fig. 26 is [a partial diagrammatic rear elevation of Fig. 25 and Fig. 27is a diagrammatic section on the line 27-27 of Fig. 3.

With my 'invention there are obtained means by which either straight ortapered teeth may be cut. By my construction forming tools as Well asthe simultaneous moving of the gear blank and cutting tools aredispensed with.

ln the drawings the numeral 20 represents a supporting base With anextei. on 40 that carries a gear blank supporting table 4l (Fig. l).The'upper portion of the said base 30 has formed therewith inverted Vguidessi)J on which is slidingly mounted a supporting plate 43. -Thelatter'has slidingly attached thereto a. sliding plate 44 from Whichextend the housings or uprights `iections and 54 on the housings 45 and111)' 46 to keep the said head 48 in alinement los therewith. A toolguide carrying ling 5 5 is i, l adjustably mounted on the h eai 48,jllrfbyf;

' the said guide ring 55 maybe swung throughy a predetermined angleas-will be more-fully hereinafter described.

The supporting and sliding plates 43 and 44 may be adjusted to locatethe tool carrying head 48 in operative position over the gear blanktable 41. Thesaid supporting plate 43 is provided with a downwardly eX-tending arm56 that is in threaded engagement with'a screw 57, one end ofwhich is Supported in a boss 58 in the left hand side 32 of the base 30.Collars 132 and 133 maintain the said'screw 57 inposition inthe boss58.- The said collar 133 is provided with graduations by which themovements of thedscrew 57 and the-plate 43 can be accuratelypredetermined (Figs. 13 andA 15). Motion is imparted to the variousinterconnected mechanisms of the machine, by means of a step cone pulley60. 'The said pulley v60 is secured to thev end of the shaft 61,adjacent to a bearing 31 formed with the base 30 (Fig. 15). One end ofthe shaft 61 is journaledin the bearing 31 and the other end in abearing 62 which is bolted to the inner face ofthe base 30 at the rearside *33 thereofi A collar 63 on the right hand end of the 'said'shaft61 adjacent to the bearing Y 62 maintainsthe said shaft 6l in position.'

miter gear v64'is slidably supported on the shaft 61, and is in. meshingengagement with a coacting miter gear 65 that is secured on one, end ofa -transverse shaft 66. The

latter is journaled in the bearings 67 and 68 extending downwardly fromthe under-V side Iof the supporting plate 43. A similarlydependingbearing 69, adjacent to the hub end of the gear l64;.maintains thelatter in engagement with. the gear (Figs. 13 and 15). A spiral gear 70is driven by the shaft 66 and is slidingly mounted thereon. The saidgear 70 meshes with a spiral gear 71 which is attached to the' lower endof av sleeve. 72, which is rotatably mounted in 'a hub 73 extendingdownwardly from the underside ofthe sliding plate 44. A collar 74maintains the saidsleeve 72 in position. A spline 75 in the sleeve`72transmits motion.

ingly connected therewith. Ears 77 formed With the hub 73 straddle thegear 70, and

keep the latter in engagement with the spiral gear 71V whilethe saidgear 70 is being translated on the shaft 66. The upper end of the shaft76 is journ'aled in a bearing 78 formedI with the head 48 in thelowerside 79 thereof. A bevel pinion 91 is keyed to the upper end of the saidshaft `'7 6, and a collar 92 on the latter adjacent to the bearing 78maintains the axial position of said shaft 76. An intermittent gear 93and a bevel gear rim 94 are secured to .one end` of a cylindrical shellby meansof bolts 96. A shank 97 extending from the former is journaledin a bearing 98,.which is bolted toan inwardly pro- `112which is 4,lv,The latter 'rs from the said sleeve to a-shaft 76 that is slidvjecting fiange 80 formed with the head 48.

The said bevel gear rim 94 meshes with the lpinion 91 whereby motion isimparted to the shell 95. A sleeve 89v is keyed to one end of a shaft99, that is journaled in a bearing 81 projecting in the head 48 at theright hand side 82 thereof. The saidv sleeve 89 has extending therefrom.a stud 100, the

outer end of which is in engagement with the shell 95, whereby rotationis transmitted bevel pinion 101 is rotatably mounted on the stud and isin meshing engagement with bevel gears 102 and 103., The latter is ro-.c

tatably mounted on the shaft 99 and the said gear 103 has keyed theretoa bevelgear 104. The hub of.

gear 104 meshes with the pinion '105, that-is keyed vto a shaft 106. Thesaid shaft 106 is j ournaled in a socket 83 formed on the upper portionof the bearing 81, and also in a'bearing 84 projecting downwardly fromthe head 48 at the top side 85 thereof. A spur pinipn 107 is secured tothe upper end of shaft 106 andv coacts with the feed mechthe la-tterforms an extension bearing lfor the shell 95. -The said bevel' anism ofthe machine which will lbe more l fully hereinafter described. vThespeed of motion as well as rotation in either direc.

is keyed to the other end of the said shaft by the gear 1.03 andA 'may108 which is supported in aA bearing 110 formed in aside cover plate111, that incloses the left hand side of the head 48. The intermittentgear 93 meshes with a pinion keyed to 011e end of a shaft 113. journaledin bearings 114 that project" downwardly 134. Alpinion 115 is keyed tothe other' end -the said shaft 113 and a spacing sleeve 135 mounted onthe latter separates the pinions 112 and 115.x The said pinion 112 hasattached thereto a locking plate 11,6 which engages a lange 117projecting from the left hand side of the intermittent gear. Recesses118 formed- 93 (Figs. 7 and 8). with the-said flange 117 adjacent totheterminal teeth 119 of the intermittent gear 93, provide clearancesfor the'eorners 120 of the locking plate 116 on 'the pinion 112, whenthe latter is turned by the said gear 93. The number of teeth on theintermittent gear '93 extends around one-half of the periphery thereofand is equal to the number.-

from a top cover plate l 75 from the said shell 95-to the shaft' 99. A

` 20 with the Aseid shell 122.

1,14s,eee

of teeth aroinid the Whole periphery of the pinion 110- by virtue ofwhich the shaft 113 has imparte-d to it one revolution for onehal.revolution of the intermittent gear 93. During the remaining halfrevolution of the gear 93, the shaft 113 is held at rest by the I lochin1ilate 116. This effect is )reduced` by virtue or" the intermittent gear93,Which is twice the diameter of the pinion 112, having teeth only onone-half of the circumferential surface. The pinion 115 gears with thegear l2* that is rotatably' mounted on the shan" i of the shell 95.,between the bevel ..09 and the bearing The said gear 121 has extendingfrom the left hand side thereof a. cylindrical shell A sleeve 123 isrotatably mounted on shaft 10S and has extending therefrom a 121., theouter end of Twhich stud is in engagement A bevel .pinion 125 isrotatably mounted on the said stud '12e and gears with the bevel gear109, end also with the bevel gearA 126. The latter is keyed on a hub 12?of a bevel gear 128. The said pinion 125 and the gears 109, 126 togetherconstitute a secondary differential mecha isin. The said gear 128 isrotatably mount ed on the left hand portion of the shaft 108 and is inmeshing engagement 'with a bevel 3g pinion 129. The latter isv securedto the upper extremity of a shaft 130A which is journaled in a. bearing86 formed with the head 18 in the underside 79 thereof. A eol- .lar 131maintains the axial position said shaft 130 in the hearing 86. The gear121 being double the diameter of the pinion 115 it makes half the numberof revolutions of the latter. The rotation of the said pinion 15 beinginterrupted by consecutive inter .9 vals of 't. as hereinbeforedescribed, the gear therefore maire a half ref/oran it vill remain atrest for the rerevolution of the said'gear 93. sleeve 123 and stud 124i,Which c pinion 125, have corre- 'riods of motion aant of being driven 1salready stated,

1439 is by interposed ineohl rejet with the pinahioh niesh with theastened to the gear 1:28 thm; coa n' the pinion 129 on the shaft 1311.Any movement imparted to the said pinion is transmitted to the saidshaft 130. The said pinion 125 has also intermittent periods ofrotationtransmitted eo thereto by the mechanism previously described by reasonof which the said shaft 13G ivi av similar periods of rotation. The sait .130 is thus actuated npon by tivo dist irate sources of motion, onee5 reed t1 g5 motion from the Yoinion of they revolution of theintermittentn ated hand Wheel screw 161. ,ai and 12.) The centraiportion 162- o the 195 also engages the- 195 positively operated fromthe feed mechf anism, and one drive motion transmitted intermittentlyfrom the said pinion 91 which is in positive engagement With the drive'mechanism. The latter motion imparted to 70 the shaft indexes the gearblank one tooth While the cutting tools hereinafter described, advancedeeper into the blank at every cutting stroke. The motion imparted bythe feed operative gear 105 controls and 75 rotates the gear blank in amanner to move block is regulated by a screw 113 that is in threadedyengagement therewith. A. collar 90 144 maintains the said screw 143 inoperative'position in the disk 110. (Fig. 12).

.The block 142 has extending therefrom a crank pin 145 that connects theone end of e connecting rod 146. The other end of the 95 said rodsupports one end of a vvrist pin 147,

the other end of which is secured in a sliding heed 118. The said head148 is slidingly mounted in an upper guide 14:9 that is bolted to thetool guide ring 55. The latter is 100 held in position against the head48 by a a plate 150. The said sliding head 118 is provided with a pairof slots 151 and clamping pins 152 are adjustably secured in the saidslots. Connecting links 153 connect the said 105 pins 152 Witha pair ofsliding blocks 154 and 155 which are slidingly mounted in theirrespective lower guides 156 and 157. (Figs. G 8) Thelatter areadjustably secured to the said tool carrying ring 55 by 110 rae-ans ofbolts 15S engaging arc shaped slots in the tool carrying ring 55. Theloiv'er guides 15G and 157 have at their rear portions the swivelsockets 160, and the said sockets are threaded internally to receive a115 a (Figs. 10,

said screw '161 is pivoted on a pin 163 that is carried in a sleeve 161which is rotatably mounted in an ear 165 extending from the 120 lowerportion of the ring 55. internally threaded collars 166 engagecorrespondingly threaded end portions of the said sleeve 16e to maintainthe latter in axial alinement with the said ear 165. By loosening the.1.25 bolts 158, the said guides 15G and 157 may be fated upon beingpivotally swiveled around the said shaft 99 a predetermined distance bythe said hand Wheel sorew 161, the obieot of which will be more fullyhere- 13C inafter described. Side portions 167 and 168 extend from therear of the said guides 156 and 157 and form therewith a rear straightsidedrecess 169. Adjacent tothe front portion of the recess 169 a frontdovetailed recess 170 and a front straight sided recess 171 are formed.The latter is provided with a beveled gib 172 that is adjusted by meansof said screws 173 which are in threaded engagement with the side 168.The sides 167 of the said guides 156 and 157 are beveled at their upperinside corners 174 and 175 to clear each other when their lower portionsare spread apart.- The said pair of sliding blocks 154- and 155, theguides 156 and 157 and the therewith connected .elements willhereinafter be described only for one side of the machine and will bereferred to as the sliding block 155 and the guide 157. Thesliding'block 155 engages the said rcar straight sided recess 169 and isconnected with a tool slide 176 by means .of a link 177. One endA of thelatter is pivoted on a .pin 178 that is carried in the said slidingblock 1554 and the other end of the said link 177 is suitably hinged toan arm 179. The latter is pivoted on a pin 180 which is ljournaled inears 181 formed with the upper portion of the said tool slide 176. A key182 secures the arm 179 to the said pin 180 and the former has extendingtherefrom ears 183 in which is rotatably carried a screw 181 which ismaintained in lalinement with the ears 183 by a collar'185. The

-said screw 184 has a threaded portion in engagement with a lug. 186that is" formed integral with an adjustable' member 187 whereby thelatter is shifted laterally on the arm 179, the purpose of which will bemore -fully hereinafter described. Bolts188 in the slots 189 clampthe-.said adjustable member 187 to the said arm 179. The latter has'formed therewith a hub 190 from the under side of which extends a lip191 that holds a cutting tool 192 against the pressure of a set, screw193 which isoin threaded engage-` ment with the said hub 190. A clampingplate 191 keeps the said tool 192 in a xed position. The said the underside of the tool 192 as well as against the ledge 195 that isformedfwith the under side ofthe said hub 190. A bolt 196 passes throughthe plate 19-1 and the hub 190 by which the tool 192 is rigidly clampedto resist thestrain thereon due to the cutting action of the latter onthe gear blank operated upon. A knee 292 extending from the tool slide176 resists the side thrust on the arm 179,. The tool` slide 176 movesi. the path of the sliding block 154 and t latter hz s atop ledge 197.and a bottom led 198. An adjusting screw 199 in the saiVL bottom ledge198 controls the vertical motion of the said slide 176, between the saidscrew and the top ledge 197. The tool slide plate 19-1 bears againstvvin contact with the top ledge 197 and on the instant of the reversal ofthe said sliding block 154.4 the tool slide 176 is at rest. At thebeginning of the upward movement of the sliding block 154: and duringthe brief interval when the tool slide 176 remains at rest the arm 179is pulled inwardly by the link 177.

The said tool slide 176 remains vmotionless during this interval due tothe' frictional resistance of the gib 172, the link 177 as previouslystated is connected up with the said sliding block 151 and therefore itmoves the cutting tool 192 inward out of cutting engagement with thegear blank operated upon as just stated; When theadjusting screw 199strikes the said tool slide 176 the latter moves upwardly with thesliding block 154. At the beginning of the return down stroke the toolslide 17 6 is at rest for another brief interval, during wliich the saidlink "177 pushes the arm 179 outwardly into operative position until thetop ledge 197 strikes the said tool slide 176 whereby the latter movesdownwardly together with the sliding block 154. The length of strokeofthe cutting tools suitable tothe Iface of the gear is obtained byadjusting/the block 142 in the disk 110. The vertical position of thesliding blocks lst-and 155 in the guides 156 and 157 is determined bythe location of the clamp pins 1,5 in the slots 151 of the sliding head148. The upp'er guide 1419 and the roo said lowerguides 156 and 157 byvirtue of being attached to the ring I55 are swiuig simultaneouslyaround the axial center of the shaft 99. Motion is imparted to the ringby means of a worm segment 200 that is secured-thereto. A worm 201engages the worm segment 200, the purpose of which will be more fullyhereinafter described.

The shaft 130 is in slidable'engagement with a sleeve 210 and impartstheretof'the intermittently feed controlled rotation' hereinbeforedescribed, by means of a suitable spline therein (Figs.v 18, 15 and 16).The said sleeve 2 10 is rotatably carried in a, bracket 211 which isbolted tothe sliding plate 14. The sleeve is maintained infaxialalinement with the said hub 211-by means of a. collar 212 that isattached to the upper end of the sleeve, and by a spiral gear 218secured to the lower end of the sleeve. The gear 218 gears with acoacting gear 21flwhich 'is held in engagement therewith by lugs 215extending from the hub bracket 211. The gear 214i is slidingly mounted'on a shaft 216 which it rotates. The latteris i journaled in bearings217 and 218 that dej mounted on the said stud 230'and is ar ranged torotate with =thefpinion 228. The

said gear 231 meshes/ with a; pinion 232that is secured to the leftVvhandl end of a shaft- -233, adjacent to a hub 234 'of an arm, 235. 'f

toi-one end thereof and by a miter gear 220 secured to itsVK other end.The teeth of the miter 220 mesh With a corresponding gearT1 221 that isslidingly mounted on a shaft'222 4 driven thereby. The right hand end ofthe said shaft 222 is journaled in a bearing 223 that is bolted to thebase on the inner face of the front side 34 thereof. A bearing 224depending from the under side of the said supporting plate 43 adjacentto the gear 221 secures engagement between the latter and the coactinggear 220. The left hand portion of the said shaft 222 passes through theleft hand side 32 of the base 30 and is journaled therein. The shaft 222is 4held from axial motion by means of a collar gears with a gear 227which is in engage- -ment with a pinion 228. The said gear-227 isrotatably mounted on a 'stud229 and the I pinion 228 is similarlymountedon a stud 230 (Figs. 5 and 15).l AV gear 231 is also' Thehcreinbefore describedfstuds 229'and 230 are adjustablymounted,` ina-slot 236 of thessaid arm 235. The latterhas an extension 237'- whichis .provided1with a slot 23S. A bolt 239 engage- Stilte saidslot 238.-land clamps the arm 235 operative position. (Fig. 5.) The 1301112239 isin threaded engagement with a hub bracket240 that is i bolted to thebase 30 at the left hand -portion of the top side 35 thereof. The 'saidshaft 233 isjournaled in ja left hand bearing 241 and inarg-right handbearing' 242 that are bolted to the front side 34 of the base 30. (Fig.i.) 1 y A miter "gear 243 is secured'to the right fhand end of the saidshaft v,233 adjacent to lthe bearing 242i The latter has formed f shaft245; isv journaled in bearings 246 and therewith at; right.anglesthereto a branch bearing 244gin which is jonrnaled one end .of ashaft A245'. The other end of the said 247 which'v are bolted to theright hand por- 'f tion of the top side 3 6 of the base 30.

(Figs. 3 4and 5.) Thesaid shaft 245 has 5 5 secured thereto a miter gear248 that gears with the gear 243. A Worm 249 is secured on the shaft 245and the former is in engagement with a worm Wheel 250. The latter hasformed With the lower portion there- .of `anj inwardly extending flange251 that is bolted to a foot flange 252 of a subtable 253.

(Fig. 1.) The said table 253 has secured thereto a socket 254 Whichreceives a man- 'drel 255 that carriesthe gear blank to. be

operated upon.` The said snbtable 253 is vis journaled'in the said box283.

journaled in an annular shell 256 that is attached to 'the main table41. The said Shell 25p has formed therewith a projecting p0rtion' 257that is pivoted on the shaft 2457 whereby the shell 256 and `thetherewith connected elements can be swung around the axial center lofthe shaft 245 While* at the same time the subtable 253 is rotated. Thesaid main table 41 has extending therefrom a toothed segment 258 that isengaged by a Worm 259 which Vis formed with a shaft 260. (Figs. 1 and4.) The latter has attached to the lower portion thereof a miter gear261 which coacts with a gear 262 that is securedto one end of a shaft263. A hand crank 264 is secured to the other end of the said shaft 263whereby .the table 41 and the,

therewith coacting elements may be swung in a predetermined angularposition relative..

a frameextension 40.

cated in a boxvframe 283, 'WhichY also coni tainsthe pinion 280. `A stud284 is carried byf'the said arm 281 and a inionf 285 is rotatablymounted on .the ormer. The teeth ofthe pinion 285 mesh '.With the teethof gear275 which is also shiftable by. the said arm 281,. The' lattergear engages .the Said pinion-280. 'The in'n 285 'cane'ngage either-'one.of gears 86,287 or 288tha't arekeyed' onone endv of a shaft 289 whichA.. predetermined relative difference in rotation can thereby betransmitted to the said shaft 289 to provide a feed suitable to theypitch and diameter of the gear blank operated upon. The said shaft 289has attached to the other end thereof a Worm 290 that meshes with a Wormwheel 291 which is secured on a shaftA 292. The said shaft 292 has oneend thereof journaled in the rear. Wall of the box 283 and the other endin a cover 293 of the said box 283, (being removed in Fig. 1.) A spurgear 294 is secured to the shaft 292 and gears with a gear 295. Thelatter is rotatably carried on a stud 296 secured in an arm 297, whichis pivoted on the said shaft 292. The said gear 295 can engage eitherone of gears 298 or 299. The former is secured to one end of a `shaft300 which is journaled in a rear portion 301 of the said bon 283. Theother 'iat - mounted in a hubI 308.

alinement.' A spiral gear 305 vis slidingly mounted on and driven by thesaid shaft 300. The former is maintained in engagement with a coactinggear 306 by a forked bracket 276 that is boltedto the sliding plate 44.The said gear 306 is secured to one end of a sleeve 307 which isrotatably The latter is attached to the under side .of the sliding plate44. A collar 309 maintains the said sleeve 307 in position in the saidhub 308 and a shaft 310 with the lower 4portion thereof in slidableengagement with the sleeve 307 is rotated thereby.v (Fig. 13.) 'D

threads 311 that engage a stationary-nut' ments manually.

The shaft 300 is provideill with screw 312 which is attached tothe'sliding plate 4:4 Wherby the Vlatter is moved transversely on thesupportng'plate 43. The said shaftv 300 has formed at one end thereof asquare suitable wrench can be applied to rotate the shaft 300 and thetherewith connected ele- (Fig. 3.) The upper end of y the said shaft 310passesv through the head 48 andis suitably journaled. in the top andbottom sides respectively 85 and 79 thereof, (Fig. 9.) A pinion 314 issecured to the top of the shaft 310, the formermesh-l ing with thegear315 that is rotatably carvried on a stud 316 which extends up from a-slotted arm 317. The said arm 317 is clamped in position by means of abolt 318 which has the lower end thereof located in j a T slot 87tha-tis formed with the top side 85 of the head 48. A gear 319 is alsomounted on the said stud 316 and is arranged'to rotate with the gear 315The said gear 319 gears with the pinion 1U? 'on the shaft 106 which .ashereinbefore described controls thev vgear blankfaotuating mechanismthrough the intervening differential gearing. By selecting a properratio of gears in the closed circuit or cycle of 'gearing between thesaid shafts 106 and 310, the rotation of thetgear blank at apredetermined angular Velocity harmonious with thel cutting tools willre" semble the action of a gear and a rack in actual mesh ashereinheforedescribed. The

motion Atransmitted by the shaft 233 to the gear blank is a simpleintermittent rotary notion in o'ne direction while the gear blanksupporting table/is held .stationary in oneI plane, which motion is the'resultant'of the combined spacing and feeding converted into a unitarymovementfor the 'indexing rof Vthe blank.

The gear 299 is secured to one end of a shaft 320 which is also journaled inthe rear o portion 301 of the box 283. The other end of theshaft 320 is supported in a bearing formed in thc said projectingportion 302.y

((lollars 277 and 278 maintain the axial alinement ofthe said shaft 320between the bearings v301 and 302. (Figs. 4 and 15.)

portion 313 to which a handcrank or other' `on top'of the head 48.-'AThe said gear A spiral gear 322 is driven by the shaft 320 and isarranged to slide thereon. Ea'rs 323 depending from the under side ofthe sliding plate 44 maintain vthe said gear' 322 in engagement with acoacting spiral gear 324. The said gear 324 is secured to the lower endof a sleeve 325 thatis rotatably su ported in a boss 326 of the housing46. 327 fastened to the upper end lofthe said sleeve 325 maintains thelatter in position. A shaft 32S. is suitably driven by the sleeve 325and is free to slide therein., The upper collar portion of thevsaidshaft 328 is located f valongside the head 48 at the rear side 88thereofby means of a bracket 329 that is attached to the former. (Fig.9.)- llhe said shaft 328.has secured thereto theworm'201 which mesheswith the.worm segment200 l of the ring 55 as previously'described. 1A'r` gear 330 is secured to the-upper extremity of the shaft 328, andgears with a pinion 331 (shown disconnected in. F ig. 9) that isrotatably mounted on a -stlid 332 which en#` tends from a slotted arm333. vThe lattergis 90.

' the head 48 by means of a bolt 334 thatjh'ls clamped'in position tothe top side85`lof the lower end'jthfe'reof in .engagement'fvith pinion331 is in engagement with a gear 385;; '1

that is similarly mounted on a stu an arm 337, whichis alsoheld in gearswith thl pinion 107 of the shaft which as already -stated controlsthefge'ar blank actuating. mechanism. Y lThe latter mechanismas 'well asthe'tool feed actuating mechanism are interconnectedandfdependent uponeachiother, The speed ofthe gear blank indexing mechanism isdirectlylj..

a-'ected by the change gears` 226-"and227, pinion 228, gear231 andpinion 232 Qnfthe. left hand side of the machine. VThe ratio" of thesaid 'change gearsfisdependent upon the munber of teeth -to beP cut onthe gear. blank' and'their proportion is predeterminedto indeX- or movethe vgear blank onetooth space for every cutting stroke of the tools.

The rotation of the shaft 233 also affectstlie y tool traversingmechanism and 'the amount Y of advanceof thalatter constitutes thefeed',` 1li which is under immediate controlv 'of'.the

shiftable pinion and ear respectively 285-v and 275 and therewit'coacting'fgears 286,' 287, 288 and pinion 280. "I'he1ratiof-of-tha120gears 314, l315and 319. on top at the `near side of the head '4 8predetermines the rela- ,tive transmission of rotation from'. the saidvshaft 310 tothe shaft 106 which. as hereinbefore described operates vthe-blank actu`- ating mechanism. The last enumerated gears are in useonlywhencutting spur and 'spiral gears, andl their proportions y.areYchanged for the different sizes otvpitch of gear teeth to be cut.- Thegears 330,331A and "235 on top at the far side of the head 48 13 inaaaoaare 'connected up with the 'gear 107 only when cutting bevel gears andsimilarly their proportions are changed `for the derent sizes or" pitchto be cut on a bevel gear blank.

From `the foregoing it will be 'seen that y `of change gears isprovided, one selected in 'accordance with the number oi teeth to be cutin the blank, and the other in conformity with the pitch to be used.These change gearsv are operatively connected up with a differentialmechanism to the feed mechanism in a closed cycle, so that themovementsof the indexing and the feed mechanism are interdependent oneupon the other. As stated, there is also provided a nest of gearsbetween the indexing aud-v the feedA mechanisms which predeterinnes therate o feed. This nest of gears controls'both the straight transversetranslatmovement and the circular. translating .movement of the tool`upon the tool head.

. The set of change gears for determining the yet nuin'ber of.l teeth'is located in' the line of niotionA whichjcoines from the reciprocating niech'anisiuv and is converted into interi' mitteilt rotarymotionadecting the indexf'ffr ingof'the blank. The other set of changev"gears, relating to the pitch, is located inthe line of :notionconnecting the feed mechanismy with the diii'erential mechanism and'returning to 'the indexing mechanism in e.

closed cycle. The advantages of maintainingea closed cycle' between thedifferent f f 'mechanisms are among, others, that if one S811. Of'changegearsy besubstituted :or the .-'otherl'lithe Vniachme can cut adifferent ber of teeth, with the same nitcli and still I maintain therelative ratio ofthe feed and indexing mechanisms. vshould becomparatively fasterffor a smaller v gear, but as it is dependent uponthe pitch 'sion'v therefor. Again, after y1substituting. wdierent changegears, A.torinstance o a finer pitch. but still retaining the same numnthemachine will automatically make proviher of teeth. the machine willautomatically index and vfeed asterlwithout any further attention. Thisreducesto a minimum the attention that needs tobegiyen to the ma# chineand permits a '-jcompariitively inoxperiencecl niechanictdrnfitwithouterrors The nest of gearsjinterposed between. the indexingmotionnndfthe 'feed motion to determine the rate of, feediisrsellectedin accordance with the material to be out, lube?.

The rete 'of speed a spur gear blank. The latter is mounted ons an arboror spindle that is secured inthe# socket on top or" the subtable 'IfileAsupporting plate 43 with the sliding plate it -l, the housings 45 and46, the head 4:8,vv the tool'gnides carrying ring 55 and the tool slides3.56 and 157 with the tools 192 aref, moved longitudinally on the l!guides l2 by the screw 57 until the nose portions of the cutting tools92 bear on the circumierential surface oi the gear blank. From thispositon the cutting tools are advanced ln describing the functions ci myinvenle tion I will ir'st describerits operation with a certain amountdepending` upon the out A to be taken on the gear blank. The teeth onthe gear blank can be finished in one or more settings and the cuttingdepth for the teeth 'is accurately adjusted by the graduated colla-r 133on the "said screw 57. (Figs. 1 and 13.) The sizes of the cutting toolsrequired depend upon the pitchA to be'cut and two sizes of said toolsare shown in full and dottedlines in Fig. 10. The cutting edges of thetools conform tothe contour of the teeth of e. rack ci equal pitch as.those required for thegear blank to be operated upon. The thickness ofthe gear teeth is controlled by the Width of the spaces between theinside edges of the no to the blocks lt and (the travel of 395 whichisrequired to` swing the arms T179 fromor into operative position)determines v the length of stroke of the sliding blocks 154 and 155 thatare connected un `with thevsliding head 148. The travel ofthe latter 13-0 is dependent upon the radius arm'of the adjustable crank p'in 145.During the 1nfterval of time when the cutting tools are on the upwardstroke and swung away from the" gear blank thelatterispindexed. By a 11bsuitable combination of the gears 226,v 227, :228, 23E and E232-outilsleft side of kthe niachine, the indexing can include one or more toothspaces at eachindesing movement of the gear blank. By spreading the toolcar-' 1 rying adjustable .members i8? the tools can cuteither on nellanks 'of one tooth or on the flanks of adjacent teeth. The' ad-...vantages of both these adiustments are that any irregularity andbacklash in the ac- 1 tuatinf.,Y niechanisrmnr springing onthe cuttingtools willb divided, because'the same point onthe gear blank is indexedin suhscqucnt revolutions thereof and it will be .minimized andreotiied., ,The cutting oper- 1 iortions of the said cutting tools 192;The 102i 'width of said spaces isregulated by then.

4ation begins when the cutting tools 192 are in the position indicatedin the diagrammatic plan view Fig. 17 which shows the right hand toolbeginning to notch the cir- L is reduced by the worm and worm gear re-yspectively 290 and 291.' The latter drives the spur gear 294 whichtransmits motion to th'egear 295 by which the gear 298 is rotated..Therotativemotion ofthe shaft 300 axially moves the nut 312 by reason ofthe screw threads 311 engaging therewith. The said nut 312 moves thesupporting plate 44 with the head 48 and the tools 192 transversely inpredetermined successive intervals while the indexing takes place. The

.cutting tools in one working cycle make one upward and one downward stroke and during the former while the v cutting tools are swung out ofengagement with the blank the indexing mechanismvis operative and thecutting tools are moved transversely mto a new predetermined position.The said transverse movement is comparatively small being reduced fromthe shaft 233 through the worm and worm gear respectively 290- and 291and the Vsaid nut and screw threads respectively 312 and 311. Thismotion is proportioned to .move the tools during a complete rotation ofthe gear blank an amount suitable for a new cut. During the 'downward orcutting stroke ofthe tools the indexing and the feed meehanisms'are heldstationary by reason of the plate 112 locking inthe iiange 117 of theintermittent gear 93.A (Figs. 7 and 8.) Consequently the loci ofthedifferent positions of the cutting tools constitute the teeth of a rack.

The central position of the tools in relation to the gear blank in shownin plan and rear elevation respectively in Figs. 18 and 19. The gearblank operated upon will rotate a number of times during thetraversingvinotion ofthe cutting tools depending upon the feed used.When the latter have entirely passed across the face of the gear blankas shown in Fig. 20 all the cutting sides and corners of the Atools havebeen in 'actual cutting contact with the gear teeth which therefore havetheoretically perfect form.

lVhen lcutting a spiral gear the tool guide vcarrying lring" 55 isrotated to an angular. position corresponding to the requisite angle'lof the teeth. This is obtained by 'manually f turning the shaft 320which rotates the shaft 328 and the worm 201 that meshes with thewormsegment 200. This position of the tools is indicated in Figs. 21 and22 and also in Fig. 4 with the exception that the guides 156 and 157 areparallel with each other instead of being inclined as shown. Otherwisethe 'operations are identically the same as for cutting spurgears.

The change gears 315 and 319 on the head 48 are also used forcontrolling the speed of the pinion 105 and therewith the coactingdifferential gearing.' f

In cutting a bevel gear the gear blank supporting table is tilted tobring a plane passing through the bottom of the gearteeth to be cutparallel with the'line of motion of the cutting tools. (Fig. 27.) Thecuty ting tools must move in paths parallel to the sides of a tooth.This .is obtained byvsuit` ably adjusting the guides' 156'and 157 bymeans of the hand wheel screw 161. The apex of the gear conehnustcoincide with the center of the opera-ting shaft 99 by reason of thetool guides 156 and 157 being pivoted rcentrally with' the said shaft99. The width of the nose portion of the cutting tools yis determined byvthe space at the small end of the gear teeth. The cutting tools onlycut on one side of the teeth due to their convergence. The said cuttingtools 192 have a reciprocating motion, while the ring 55 to which theguides for the said tools are attached is rotated. By the lat- ,teraction of the tools their consecutive positions assume the lociof acrown gear, the teethof which latter represent the diferentf positionsof the cutting tools 192. In the latter case the initial cuttinggtakesplace `on the circumferential surface of the blank and as the toolsswing, the notches deepen until the tools have swung towardtheoppositeside of the machine .and thevtools are out of engagement With'theblankvwhen 110 the cutting is completed. The cutting tools canv embraceeither one or two teeth Hanks as shown in Figs. 23 and 25.l flhe s'wi g4ing or oscillating motion ofthe tools which constitutes the feedise'ectedbyfthe gear 115 -295 of the arm 297,'engaging th ,y ear299 onthe shaftv320 by which -niotion'fis trans: mitted to the shaft 328through the coacting spiral gears 322 and-32 4.. The worm 201 l on thesaid shaft 328 meshes with the worm 120 segment 200 of the tool guidering55, where-v by the cutting toolsy are swung into and away fromcutting' engagement with the gear blank.r The gears 331 and 335 connectthe shaft 328 with the differential gear- '125 ing in the head 48 bymeans ofthe pinion107. Havingdescribed my invention what I desire tosecure by Letters Patent and claim is;

1. A gear cutting machine comprising a 1.30

